This invention relates to a fish finder or depth detector for a marine propulsion device and more particularly to an improved, compact and highly effective depth finder for such a device.
In conjunction with watercraft it is a common practice to provide a device for finding depth or fish. Such devices operate like a sonar system and include a transmitter/receiver that emits signals which are reflected off the bottom of the water or fish to provide a signal and indication to the operator of the watercraft. Either depth finders or fish finders are generically referred in the specification and claims of this application as "depth finders". In connection with some type of watercraft, the transmitter/receiver and display are substantially separate items that must be mounted independently on the watercraft. Although this has advantages for permanent application, it does not afford an operator the ease of mounting the unit on individual and separate watercraft. Specifically, it is desirable to provide a completely self-contained unit that may be carried as a unit by the propulsion device of the watercraft and, accordingly, can be connected to the watercraft as a unit with the propulsion device.
It is, therefore, a principal object of this invention to provide a combined marine outboard drive and depth finder for attachment as a unit to a watercraft.
It is a further object of this invention to provide a combined outboard drive and depth finder wherein the outboard drive carries both the transmitter/receiver and also the display of a depth finder.
In conjunction with the mounting of the transmitter/receiver, it has been proposed to mount such unit in proximity to the propulsion unit of the outboard drive. One way that this can be done is to mount the transmitter/receiver in the skeg of the outboard drive. In this way, the transmitter/receiver is disposed at a sufficient depth so as to be unaffected by bubbles and turbulence caused by the passage of water along the bottom of the hull of the watercraft. However, in such a location the transmitter/receiver can easily become damaged if an underwater obstacle is struck.
It is, therefore, a further object of this invention to provide an improved mounting arrangement for the transmitter/receiver of a depth finder for an outboard drive.
It is a further object of this invention to provide an improved mounting arrangement for a transmitter/receiver which will not interfere with the water flow and also which will protect the device in the event underwater obstacles are struck.
Although there are advantages to mounting the transmitter/receiver in proximity to the propulsion unit, the propulsion unit can cause turbulence or create noise that will give rise to incorrect signals from the depth finder. However, if the transmitter/receiver is positioned remotely from the propulsion unit, there is the disadvantage that other turbulence created by the passage of the hull through the water will give erroneous signals.
It is, therefore, a further object of this invention to provide an improved mounting location and device for the transmitter/receiver of a depth finder on an outboard drive so as to provide good results and adequate protection for the unit.
In order to provide a unitary assembly and one which can be conveniently installed, there are advantages in providing the display of the depth finder so that it will be mounted on the outboard drive. However, because of the fact that the outboard drive contains a number of moving components which vibrate, there are disadvantages to such mountings for the display unit. That is, it is important to ensure that the display unit is not adversely affected by the vibrations occurring within the outboard drive.
It is, therefore, a still further object of this invention to provide an improved mounting arrangement for the display unit of a depth finder upon a marine outboard drive.
Many forms of marine outboard drives are mounted for movement relative to the hull of the associated watercraft. For example, the outboard drive may be mounted for pivotal movement about a vertically extending steering axis for steering of the outboard drive. In addition, the outboard drive may also be supported for pivotal movement about a horizontally disposed tilt axis for trim adjustment of the outboard drive. When it is necessary to transmit a signal from a transmitter/receiver to a display unit, it is important to ensure that this pivotal movement does not interfere with the conductors that convey the signal between the transmitter/receiver and the display unit.
It is, therefore, a still further object of this invention to provide an improved arrangement for transmitting signals between the components of a depth finder in a marine outboard drive.